Respuesta :

4 x^2 + 28 x + 49 = 0
Divide both sides by 4:
x^2 + 7 x + 49/4 = 0
Write the left hand side as a square:
(x + 7/2)^2 = 0
Take the square root of both sides:
x + 7/2 = 0
Subtract 7/2 from both sides:
Answer: x = -7/2